All posts tagged ‘Astronomy’

In 1604, a new star appeared in the night sky. It shone brighter than all the other stars and for three weeks it was even visible during the day! This mysterious beacon marked the explosive death of a nearby star. These explosions are called supernova, and they give off so much light that for a few weeks, they can outshine a galaxy of billions of stars! Then slowly they fade away, leaving behind beautiful glowing clouds of gas, like the one in this picture.

But let’s travel back to a few millions years earlier, because the story of this star gets even more interesting. The star that exploded in 1604 began its life as an average star, similar to our Sun. When an average-sized star dies, the result is much less dramatic than a powerful supernova. Instead of exploding, they collapse. The material from the centre of the star ends up squashed tightly down into a tiny, heavy ball called a white dwarf star.

This is how this star died for the first time, long before 1604. But how did it end up dying a second time? Well, astronomers have recently discovered the answer to that question. The white dwarf had a companion, an enormous red giant star. Even though the red giant was much larger, the white dwarf’s gravity was much stronger. It began to rip gas off its companion, pulling the material onto itself. Eventually the star’s own greed led to its demise. It stole so much material that it became unstable, leading to the spectacular explosion that our ancestors saw!

More Information: The astronomers who made this discovery have created a video showing a simulation of the supernova explosion; you can watch it here and get an amazing close-up view of one of the most explosive events in nature!

The weekly Star Scoop is a new feature, courtesy of EU Universe Awareness, dedicated to the mission to to educate children aged 4-10 years (especially those from underprivileged communities) about astronomy, because it embodies a unique combination of scientific and cultural aspects.

A crater near Mercury’s north pole has been named for J.R.R. Tolkien. (Photo: NASA/MESSENGER)

Geeks cried “Huzzah!” this week when, in a curious “worlds collide” collision between fantasy and science, a crater on the planet Mercury was named after J.R.R. Tolkien.

According to International Science Times, Tolkien, the author of The Hobbit and The Lord of the Rings, has been “immortalized on a cosmic scale” when scientists added Tolkien’s name, along with the names of eight other international artists, to several features on the surface of Mercury.

“The names were approved by the International Astronomical Union on August 6, and are all craters near Mercury’s northern pole,” said the news report. The ” Tolkien crater” is a “fairly large” one, as far as craters on Mercury go: some 30 miles in diameter.

Imagine that you’re an astronomy enthusiast with the financial resources of Bruce Wayne or Tony Stark — what would you do to feed your hobby? Well, obviously you’d launch your own Hubble-esque space telescope, which is kind of ridiculous, so forget that.

Okay, instead imagine that, rather than a billionaire, you’re merely a millionaire with a passion for astronomy — now what do you do? The answer in this case is to build an amazing backyard observatory, which is exactly what the father of a lucky 19-year-old Reddit user did.

The telescope required a crane to lower it into place

Kakon24 over at Reddit has posted a series of pictures detailing the construction of an incredible “backyard” observatory. As well, the Redditor took the time to answer questions about the telescope and related matters. And as you might expect, the Reddit discussion gets into plenty of technical detail for those interested:

With our equipment we can get 0.39 arc seconds per pixel which is 7x better than we are able to see due to our altitude.
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Yes, some serious kung-fu on the mirrors, which is what makes RCOS one of only a small handful that makes true RCs. The primary took over a year to make, and was finished using ionic milling to make the surface good to 1/40th of the wavelength of light on average.
…
We use an APOGEE AFW50s-10 which is a 10 position 50mm sq filter with L, R, G, B, Ha, OIII, Sii, B, V and R filters. Last three are Johnson Cousins photometry filters and the three before that are narrowband for specific emission lines.

Personally, I was most surprised by the measures required to clean the hardware:

They recommend spraying with frozen CO2 once a year or so if the mirror has only dust. You need medical grade liquid CO2 and a special spray gun designed for cryogenic gases. It comes out as snow flakes of pure CO2, which you spray directly on the mirror and runs off taking the dust with it, and then sublimates directly into CO2 gas.

The temp and humidity can change dramatically during an evening, even with the dome closed, and there can occasionally be condensation on the mirror that makes the dust and pollen adhere to the mirror surface that can’t be removed using CO2. For that, we use a polymer cleaner than you spray on, let dry, then peel off.

You can see a dark area between the edge of the Sun and the edge of Venus. Click to embiggen. Photo: Jenny Williams

I am fortunate to live in a town with plenty of astronomy enthusiasts. There is a very active Astronomy Club, and plenty of amateur astronomers with their own telescopes. I even have my own (a six inch Dobsonian reflector). A friend of mine has several solar telescopes, and a bunch of us gathered to watch the transit of Venus across the Sun yesterday. (If I weren’t so lucky to have this friend, there were several places around town that I could have gone to view the transit.)

You can see light around the entirety of Venus, if you look closely. Click to embiggen. Photo: Jenny Williams

We gathered in advance of the transit, and got the telescopes all set up. Where I live in Arizona, we would get to see Venus starting to cross the Sun, but the Sun would set before we’d see Venus exit. But we made the most of our opportunity.

Peeking in each of the telescopes every couple of minutes, I got to see Venus as it just barely touched the edge of the Sun, then I got to see where Venus wasn’t quite totally in front of the Sun but the corona lit the entirety of Venus from behind. Then I managed to get several pictures of the optical illusion of a dark area between Venus and the edge of the Sun as it got swallowed up.

I still had some eclipse glasses from the recent solar eclipse, so we used those as well. Those with a keen eye could see Venus in front of the face of the Sun.

We all stopped looking in the telescope quite as often while Venus crawled slowly across the Sun’s surface. But even though the images to see at that point were less exciting, the importance and rarity of this event still wasn’t lost on us.

How did you experience the Venus transit? Did you gather with friends, kids running amok, and spend the afternoon gazing at the sun? Or did you head to your local library, community college, or observatory and share with the public? Regardless, I hope most of you were able to witness this twice-in-a-lifetime event.

You can get a map of when the transit will be visible in your location. Image: transitofvenus.nl

On Tuesday, June 5, observers around the world will be able to watch the planet Venus as it crosses between Earth and the Sun. Here on Earth, the Transit of Venus will look like a tiny black dot moving in an arc across the upper right hand corner of the disc of the sun.

In North America, the transit should start around 6 p.m. EDT and be visible until sunset. A great website for information on this rare event — which won’t occur again in this century — is transitofvenus.org. You can also watch the transit live from the SLOOH space camera.

And for a neat visual key that shows when the transit will be visible from your location, go to transitofvenus.nl.

If those of you around the Pacific didn’t get enough of safely staring at the sun during the recent eclipse, keep those solar glasses handy because on June 5th for those of us in the Western Hemisphere (and June 6th for everyone else) there will be another opportunity to use them. On those dates Venus will travel across the face of the sun. In the scientific community this is known as a “transit of Venus.” You can learn all you want about the coming event over at transitofvenus.org.

Apparently this is a pretty rare event which won’t happen again in our lifetime. The little explanatory video above gives a really wonderful explanation of why the transit of Venus has been so important to the scientific community. Frankly I wasn’t nearly as excited until I saw the video.

When it comes to astronomical photography, results are often governed by location, location and location. This was certainly the case for Don Pettit, who, like many before him, decided to take long-exposure pictures to capture the trails of stars as their positions relative to the Earth changed. There was one chief difference for Pettit, though: He took the pictures while an astronaut on the International Space Station.

Pettit’s experiment produced a series of amazing pictures, which photographer Alan Rivest then used to assemble a time-lapse video. Not only are the star trails beautiful, but the video also captures auroras and lit-up cities at night, among other things.

If this video isn’t the most beautiful 200 seconds of your day, I’ll be surprised.

Today in 1930, Clyde Tombaugh discovered Pluto! Although the discovery wasn’t announced by the Lowell observatory until early March. Recently that rebellious little ball of ice may have been kicked out of the planet club, but its discovery by the amateur assistant Tombaugh still remains a potent symbol for the value of amateur astronomy.

Back in December, PBS ran a great NOVA on both Tombaugh and the controversy. The video of the full show can be found for free on their site. If you missed it, today would be a great day to catch the humorous and informative show. Besides, it’s hosted by GeekDad’s favorite astronomer Neil deGrasse Tyson. Tyson is scheduled to host an update of Carl Sagan’s famous Cosmos television series. We are looking forward to it!

I’ve seen some pretty wonderful interactive programs that allow you and your family to explore the vast regions of the universe, but nothing nearly as enthralling as Universe Sandbox. In a nutshell, it is an interactive program that allows you to explore our solar system, galaxies and the universe. It also allows you to manipulate certain variables and witness how those changes would effect the universe.

At this playground in Italy, the earth is still at the center of the solar system

Galileo Galilei (1564-1642), aka Galileo, had this crazy idea that perhaps the earth was not at the center of the solar system or for that matter, the center of the universe. In his day, most philosophers and astronomers believed in the geocentric view: that the Earth was at the center. Same with the Church, which didn’t much like Galileo’s ideas. It wasn’t until 1992 that Pope John Paul II finally and officially apologized for how the Galileo affair was handled.

You’d think that the debate over Copernicanism (which took Galileo’s side and argued for a helio-, or sun-centric, model of the solar system) would be pretty much settled by now.

So imagine my surprise when today, vacationing in Genova, Italy, I noticed a curious item near Genova’s Porto Antico (Old Port). This is one of those activity-learning stations you see in public playgrounds. There’s a rocket you can move from planet to planet (it slides along a groove), but the planets are in a completely random order: you travel from the moon to Venus, then Jupiter, then Neptune, etc, and back to Mars. And guess what? As you can see, the earth is in the middle.

Yep, right here in Italy, where the controversy all began, and the earth is the center of attention once again. And I thought Creationism had a nice story to tell.